/**
 * PXM Dropdown Submenu Wrapper Component
 *
 * Wraps a submenu trigger and content, managing open/close state and interaction mode.
 * Usage:
 * <pxm-dropdown-submenu open-on="hover|click">
 *   <pxm-dropdown-submenu-trigger>More…</pxm-dropdown-submenu-trigger>
 *   <pxm-dropdown-submenu-content>...</pxm-dropdown-submenu-content>
 * </pxm-dropdown-submenu>
 */
export declare class PxmDropdownSubmenu extends HTMLElement {
    private _open;
    private _openOn;
    private _trigger;
    private _content;
    static get observedAttributes(): string[];
    constructor();
    connectedCallback(): void;
    disconnectedCallback(): void;
    attributeChangedCallback(name: string): void;
    private _findParts;
    private _applyOpenOn;
    private _removeListeners;
    private _onOpen;
    private _onClose;
    private _onToggle;
    private _onKeyDown;
    private _onPointerLeave;
    private _updateState;
    closeSubmenu(): void;
}